Staff: Mentor

I'm no expert on this topic, but I note that 10^-22 is the volume of the sample they are using (100 x 100 x 10 nm3) in cubic meters. I note also that the units of their formula work out to J-1 m-3, so to yield a result in J-1 multiplying by a volume is called for.

I further note that their intermediate result: 1.51 x 1056 m-3 J-1 is suspect. Plugging in their values I get an order of magnitude of 1046 rather than 1056, however their final result looks fine.

Are you sure you posted all of the information given in the question? You need the effective mass of electrons and holes in germanium to work that out. (The values are very different to the values for silicon.)